Reinforcing heel insert and heel



Oct. 15, 1963 A. F. BALL 3,106,791

REINFORCING HEEL INSERT AND HEEL 7 Filed Nov. '16, 1960 INVENTOR.437790358414 BY m W a AIIDfMfV-S' United States Patent 3,106,791REINFORCKNG HEEL INSERT AND HEEL Arthur F. Ball, Haverhill, Mass.,assignor to Essex Products, Inc, Haverhill, Mass a corporation of Massa=chusetts Filed Nov. 16, 1950, Ser. No. 69,689 8 Claims. {CL 3634) Thepresent invention relates to reinforced heels for shoes and the like andreinforcing components thereof, being more particularly directed toplastic heels.

In my copending application, Serial No. 731,040, filed April 25, 1958,for Reinforced Heel, Insert and Method, there is disclosed a novelinsert or dowel that provides structural rigidity to thin-stem plasticheels and the like, with insurance that the reinforcing dowel employedtherein cannot move in any direction within the stem, and with the addedfeature of securing a toplift to the heel that cannot separate or moverelative to the heel and its reinforcing dowel. While this invention hasbeen found to work admirably well in practice, there are occasions wherecertain materials that are particularly impact-stretchable are employedas toplifts, markedly increasing the tendency for the loosening ordeterioration of the toplift itself, during use.

It is to this problem that the present invention is primarily directed,dealing with a new and improved reinforcing dowel or insert of the typedisclosed in the said co-pending application that is more particularlyadapted for utilization with molded plastic lifts and the like,particularly where plastic materials are employed that are of the typesthat tend to stretch upon impact.

A further object of the invention is to provide a new and improvedheel-reinforcing dowel.

Still an additional object is to provide a new and improved heel of thecharacter described.

Other and further objects will be explained hereinafter and will be moreparticularly pointed out in connection with the appended claims.

In summary, however, from perhaps its broadest point of view, thepresent invention involves the employment of a longitudinally extendingreinforcing dowel of hard metal and the like for a relatively fragileheel, the dowel being provided at one end with a head of cross-dimensionlarge compared with that of the body of the dowel and provided along theperiphery of the head with longitudinally extending separatedprojections. Preferred constructional details are set forth hereinafter.

The invention will now be described in connection with the accompanyingdrawing, FIG. 1 of which is a perspective view of a reinforcing dowel orinsert embodying the invention in preferred form, and secured to atoplift;

FIG. 2 is a fragmentary longitudinal view of the lower end of the dowel;

FIG. 3 is a view similar to FIG. 1, upon a somewhat reduced scale, of aheel strengthened by the insert of FIGS. 1 and 2 and provided with atoplift secured thereto through the medium of that insert; and

FIGS. 4 and 5 are fragmentary views, similar to FIG. 1, of modification.

A reinforcing dowel insert of the general type described in the saidcopending application is illustrated at 11, as of hardened steel and thelike, intermediately provided with ridge means 15 for driving into thewalls of a recess 9 in the thin stem 5 of a plastic or similar heel 1,FIG. 3. The recess 9 extends from the lift end 7 of the heel toward theheel seat 3. The ridge means 15 is shown in the preferred form of aplurality of separated sections, though continuous ridge means or othersecuring means may be employed, as disclosed in the said copendingapplication; in all cases, the ridge means 15 being of slightly greaterdiameter than the body of the dowel 11 and 3, 1 0 6,791 Patented Got. 15, 1 963 "ice slightly greater than the corresponding diameter of therecess 9 in the heel stem 5, in order that the driving of the insert 11into the recess 9 will secure the dowel against all possiblelongitudinal, circular or other movement therein.

The longitudinally extending dowel 11 is provided with a head 17 whichis of diameter much larger than that of the ridges 15, and thatprotrudes below the lift-receiving region 7 of the heel stem 5, when thedowel is driven into the recess 9. The periphery of the dowel head 17 isprovided with alternately upwardly and downwardly longitudinallyextending projections 2 and 4. The projections of the set of upwardlyextending projections 2 are spaced or separated from one anothercircumferentially about the periphery of the head v'17, as are thedownward projections of the set of projections 4, with the projections 2being interlaced between the projections 4 and extending upward from thespace between adjacent downwardly extending projections 4, for animportant purpose, later described.

It has been found that when impact-stretchable plastic of the typebefore mentioned is molded about the head 17 and the sets of projections2 and 4-, it is necessary not only to provide suflicient locking andsecuring to the plastic, but sufficient points of resistance to thetendency of the plastic to stretch upon impact and the like, as well. Tothis end, experimentation has demonstrated that the shape of one of thesets of projections, shown as the downwardly extending projections 4, ispreferably made substantially rhombic, which term is intended to connotegenerically diverging or converging side edges 4' for the projections.In FIG. 1, the spaces between the projections 4 will also definesubstantially rhombic areas 6. Above these substantially rhombic areas6, the preferably substantially rectangular projections 2 extendupwardly from the periphery of the head 17. This construction mayreadily be obtained by bending upwardly successive segments of aperipheral flange of a larger-diameter head 17 to form the projectionsor prongs 2, and then bending downwardly the remaining peripheralportions adjacent thereto, as at 4, in manner so as to providenonparallel diverging or converging side edges 4. The projections 4 arepreferably also bent either inwardly or outwardly to provide a somewhatarcuate, rather than straight rightangular, locking pocket 4-" betweenthe inner surfaces thereof and the head 17.

The dowel 11 is then ready for insertion within a jig, not shown, thatreceives the lower ridged portion of the dowel and seats the toplift end17 thereof in a cavity that is to be filled with the plastic materialfrom which the toplift 8 is to be molded. A somewhat tapered section 1%is provided, preferably of greater diameter than that of the ridges 15,and converging slightly from the head 17 to insure that, when the head17 is seated in the mold cavity, the free edges of the projections 2 arefree of the bottom wall of the cavity and thus can be adequatelycovcred-over with the plastic lift-producing material. Successiveconcentric regions '10 and 10' are thus provided between the head 17 andthe ridges 15 that are, respectively, of greater and less diameter thanthe ridges 15, and the upper projections 2 at least in part overlapportions of the region 10. Through this technique, it is insured thatthe molded plastic not only covers the complete extent of the upward anddownward projections 2 and 4, but extends within and locks between theinner surfaces of the projections 2, the upper face of the head 17 andthe adjacent portion of the dowel 11, as well as within the rectangularspaces between projections 2. and the intermediate lower substantiallyrhombic spaces 6 between the projections 4, and within the volumebounded between the projections and the lower face of the head 17.

greener Under these circumstances, it has been found that even the typeof stretchable plastic materials above referred to, are imbued with asufficient and appropriate distribution of points or regions ofresistance to spreading or stretching provided by this geometricalconfiguration, in accordance with which the upper rectangular volumesbetween projections 2 are interlaced between the lower substantiallyrhombic volumes between projections 4, so as to enable even theseplastics to be successfully employed in accordance with the presentinvention.

As a typical illustration, 2. dowel 11 for a spike plastic heel may bemade of No. 1039 steel wire hardened to 4548 on the Rockwell-C scale,having a body diameter of about 0.141 inch, ridges 15 of about 0.145inch diameter, a head 17 about 0.250 inch in diameter, projections 2 and4 of overall width about 0.1 inch, and a tapered section 10 reducing toa diameter about 0.148 inch. Such a dowell 11 has been found extremelysatisfactory for use with urethane, polyurethane and otherimpact-stretchable plastic lifts, including, also, some forms of nylonand the like, which, however, unlike the urethane, are much moreresistant to stretching under impact.

In all cases, the height of the molded lift 3 will be slightly greaterthan the over-all height of the oppositely extending projections 2 and4.

In some instances, only the downward projections 4 may be desired, as inthe embodiment of FIG. 5; whereas, in other applications the set ofupward projections alone may be used, FIG. 4. The downward and upwardsets of projections may also be interchanged, if desired, and theprojections 4 may alone be used as upward projections. When the downwardprojections alone are used, however, as in FIG. 5, the same advantagesas exist in the embodiment of FIG. 1 obtain wherein the downwardlyextending projections serve also to assist as Wearing surfaces as theplastic heel becomes worn away.

Further modifications will occur to those skilled in the art and allsuch are considered to fall within the spirit and scope of the inventionas defined in the appended claims.

What is claimed is:

1. A longitudinally extending reinforcing dowel of hard metal and thelike, for a relatively fragile heel, provided at one end with anintegral head of cross dimension large compared with that of the body ofthe dowel and provided at a plurality of spaced regions along theperiphery of the head with a corresponding plurality of longitudinallyextending projections, said projections diverging from said head aboutbending lines which are substantially circumferential with respect tothe axis of said dowel and being separated from the body of said dowelwith their major inner surfaces facing said axis.

2. The invention of claim 1, said head having at a plurality of spacedregions interlaced with the first-mentioned spaced regions anotherplurality of projections, the

A. projections of the first'mentioncd plurality extending in a directionopposite to the direction of the other plurality.

3. The invention of claim 2, the projections of one plurality havinggreater area than the projections of the other.

4. The invention of claim 2, said dowel having a lift of plasticmaterial that tends to stretch under impact molded over said head, withplastic received within the spaces between and locking to theprojections, the head, and the adjacent portion of the body of thedowel, the height of said lift being only slightly greater than theoverall height of said oppositely extending projections.

5. The invention of claim 1, said major surfaces being substantiallyrhombic.

6. The invention of claim 1, the body of said dowel being intermediatelyprovided with ridge means of predetermined diameter, the portion of thedowel disposed between said head and said ridge means having first andsecond successive regions of diameter greater and less than the saidpredetermined diameter, respectively.

7. The invention of claim 1, said dowel being provided with aconvergingly tapered section adjacent said head.

8. In combination, a fragile plastic heel having a narrow longitudinalstem recessed from a lift-receiving end upward to a heel seat, areinforcing dowel of hard metal being intermediately provided with ridgemeans of crossdimension slightly larger than that of said recess andbeing driven into said recess and locked within the walls thereof, saiddowel having at one end an integral head located below the lower end ofsaid recess, said head being of larger cross-dimension than said ridgemeans and having at a plurality of spaced regions along its periphery acorresponding plurality of longitudinally extending projections, saidprojections diverging from said head about bending lines which aresubstantially circumferential with respect to the axis of said dowel andbeing separated from the body of said dowel with their major innersurfaces facing said axis, and a lift of plastic material that tends tostretch under impact molded over said head and projections with theplastic received within the spaces between and locking to theprojections, the head, and the adjacent portion of the body of thedowel, the upper surface of the lift contacting the lift-receiving endof the heel stem.

References Cited in the file of this patent UNITED STATES PATENTS2,937,461 Trela May 24, 1960 FOREIGN PATENTS 1,227,916 France Mar. 7,1960 1,238,402 France July 4, 1960 826,006 Great Britain Dec. 23, 1959847,575 Great Britain Sept. 7, 1960 853,118 Great Britain Nov. 2, 1960

1. A LONGITUDINALLY EXTENDING REINFORCING DOWELL OF HARD METAL AND THELIKE, FOR A RELATIVELY FRAGILE HEEL, PROVIDED AT ONE END WITH ANINTEGRAL HEAD OF CROSS DIMENSION LARGE COMPARED WITH THAT OF THE BODY OFTHE DOWELL AND PROVIDED AT A PLURALITY OF SPACED REGIONS ALONG THEPERIPHERY OF THE HEAD WITH A CORRESPONDING PLURALITY OF LONGITUDINALLYEXTENDING PROJECTIONS, SAID PROJECTIONS DIVERGING FROM SAID HEAD ABOUTBENDING LINES WHICH ARE SUBSTANTIALLY CIRCUMFERENTIAL WITH RESPECT TOTHE AXIS OF SAID DOWELL AND BEING SEPARATED FROM THE BODY OF SAID DOWELWITH THEIR MAJOR INNER SURFACES FACING SAID AXIS.